mysql query help

[Rickie3]

i'm trying to execute a query for a hack,query as follows

alter table user add timespent int not null;

when i run the query this is the error i get

Error

SQL-query:

ALTER TABLE user ADD timespent int NOT NULL

MySQL said: Documentation
#1146 - Table 'satsfge_.user' doesn't exist

in the instructions for the hack it says
Run the following queries. You can do it via phpmyadmin, or at the
"Execute SQL Query" section at the Admin Control Panel
Remember to prefix the table if you need to.
any help appreciated